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Summary Of Data And Results Great Artesian Basin, South Australia Delhi-Santos Gidgealpa No. 2 And No. 3 Wells Of Delhi Australian
Petroleum Ltd And Santos Limited

Abstract

Delhi-Santos Gidgealpa No. 2 Well was located in the Coopers Creek area in the far north-eastern corner of South Australia,
two miles due west of Delhi-Santos Gidgealpa No. 1. The well was drilled by Drilling Contractors (Australia) Fty Ltd for Delhi
Australian Petroleum Ltd and Santos Limited, to a total depth of 9020 feet. Drilling commenced on 12th December, 1963, and
was completed on 10th February, 1964. A full programme of logging, testing, and coring was undertaken.
Mter passing through 618 feet of Recent and Tertiary sediments, the well penetrated 2277 feet of Upper Cretaceous, 1970 feet
of Lower Cretaceous, 1681 feet of Jurassic, 124 feet of Triassic, and 182 feet of Permian. Below the regional angular unconformity
at the base of the Permian at 6868 feet, a thick series of early Palaeozoic or Proterozoic tuffs and trachytic lavas was drilled
to total depth. This series was in marked contrast to the Cambrian sediments found below the Permian in Gidgealpa No. 1.
Gidgealpa No. 2 was drilled primarily to test the Permian and Cambrian potential reservoir beds found in Gidgealpa No. I,
in a favourable structural position. The No. 2 well was drilled high on the Gidgealpa structure, immediately after the completion
of the No. 1 well which was located on the flank of the anticline. The formations encountered in Gidgealpa No. 2 down to the
base of the Permian section, were found to be lithologically the same as in Gidgealpa No. I, but they are thinner, the Winton
Formation, Lower Triassic, and Permian rocks markedly so.
Thirteen drillstem tests were run over intervals between 6465 and 7595 feet. Five of these tests were run in open hole and
the remainder through perforations in the 7" casing. Four of the tests yielded substantial quantities of gas, and the well
was completed as a shut-in gas well capable of yielding 11.6 million cubic feet of gas and 42 barrels of condensate daily,
through a half-inch choke at a pressure of 2015 psi., from four Permian sandstones with a combined thickness of 61 feet. The
calculated absolute open flow potential of Gidgealpa No. 2 was 29.5 million cubic feet of gas per day.
The test drilling operation at Delhi - Santos Gidgealpa No. 2 was subsidized under the Petroleum Search Subsidy Act 1959-1961,
from surface to total depth.